In general, a semiconductor light emitting device, having advantages as a light source in terms of output, efficiency, and reliability, has been actively studied and developed as a high output, high efficiency light source that may be used in a backlight of a display device or in various illumination devices.
In order to use an LED as an illuminating light source commercially, an LED may be required to have high luminance efficiency and incur low fabrication costs, while providing a desired high level of output. However, if a rated current is increased to obtain a high luminous flux in an LED chip having the same area of a high output LED, a current density may also be increased, thereby degrading luminance efficiency and heating the device. The degradation of luminance efficiency may be accelerated due to the heating of the device.
Meanwhile, in order to alleviate the problem of current density, a method of increasing the area of an LED chip may be considered. But, in this case, it may be difficult to implement a uniform current density across the entire area of the chip and a high production yield may be difficult to obtain.
Thus, as a solution to the problem, a method of implementing an epitaxial layer, for an LED grown on a single substrate, into a plurality of LED cells through an isolation process and connecting the plurality of LED cells may be taken into consideration. Here, during the isolation process, sloped surfaces of the respective LED cells are required to be sufficiently gentle for a metal for connecting the plurality of LED cells to be easily deposited thereon. In this case, however, since a large region of the epitaxial layer may be removed during the isolation process, an effective light emitting area (i.e., the area of an active layer) may be drastically reduced.
Therefore, a multi-cell semiconductor light emitting device having enhanced luminance efficiency by minimizing a reduction in an effective light emitting area through an isolation process, and a fabrication method and application product thereof are required.